使用Selenium和Chrome另存为PDF

Question

我正在尝试使用打印对话框另存为pdf，这是一个我已经使用Selenium和无头铬(v81)登录的网页。所有文章声明我应该能够使用kiosk模式将文档打印/保存为pdf，其中打印到pdf会自动发生，因此预览对话框被抑制，例如

I cannot get Chrome to default to saving as a PDF when using Selenium Selenium Chrome save as pdf change download folder

到目前为止，我有以下代码：

                    ChromeOptions chromeOptions = new ChromeOptions();
                    chromeOptions.AddArguments("--headless", "--disable-infobars", "--disable-extensions", "--test-type", "--allow-insecure-localhost", "--ignore-certificate-errors", "--ignore-ssl-errors=yes", "--disable-gpu", "--kiosk-printing", "--allow-running-insecure-content"); 
                    chromeOptions.AcceptInsecureCertificates = acceptInsecureCertificates;
                    chromeOptions.UnhandledPromptBehavior = UnhandledPromptBehavior.Ignore;
                    chromeOptions.AddUserProfilePreference("print.always_print_silent", true);
                    chromeOptions.AddUserProfilePreference("download.default_directory", @"C:\Temp");
                    chromeOptions.AddUserProfilePreference("savefile.default_directory", @"C:\Temp");
                    chromeOptions.AddUserProfilePreference("download.prompt_for_download", false);
                    chromeOptions.AddUserProfilePreference("printing.default_destination_selection_rules", "{\"kind\": \"local\", \"namePattern\": \"Save as PDF\"}");
                    chromeOptions.AddUserProfilePreference("printing.print_preview_sticky_settings.appState", "{\"recentDestinations\": [{\"id\": \"Save as PDF\", \"origin\": \"local\", \"account\": \"\" }],\"version\":2,\"isGcpPromoDismissed\":false,\"selectedDestinationId\":\"Save as PDF\"}");                    
                webDriver = new ChromeDriver(ChromeDriverService.CreateDefaultService(), chromeOptions, TimeSpan.FromMinutes(timeoutMinutes));

然后我使用下面的代码打印页面：

        var driver = FeatureContext.Current.GetWebDriver();
        driver.ExecuteJavaScript("window.print();");

但我看到打印预览对话框，总是和我的默认打印机设置，而不是另存为PDF。

但是，我会使用chrome命令行，因为我需要登录到该站点。上面的代码有什么问题？

Answer 1

Selenium 4有一些新特性，比如通过ChromeDevTools实现的"Executing Command“。有了这个特性，我们可以直接从chrome调用类似"PdfAsync“的东西(像Puppersharp，但是使用selenium)。但不幸的是，我们还没有在c#中启用此选项。“Print-pdf”在未来会更容易。

然而，使用selenium 3.141.0，在web主题中做了一些搜索，我在您的代码的帮助下解决了这个问题。我在将字符串C#转换为json对象时遇到了一些问题。

使用chrome中的Logging来提供帮助。

更新27/07/2021：不幸的是，使用参数"headless“的"window.print()”将不起作用。

我的最终代码是：

public class Program
...

static void Main(string[] args)
{
     private static IWebDriver _driver;
     private static ChromeOptions _chromeOptions;
     private static ChromeDriverService _chromeService;
     private static string pathLogChromeDriver = "chrome_driver_logs";
     private static string nameFileLog = "chromedriver.log";

     //creating chrome service, to logging
     _chromeService = ChromeDriverService.CreateDefaultService(".");

     //using to see the modifications in google chrome arguments
     _chromeService.LogPath = Path.Combine(Directory.GetCurrentDirectory(), pathLogChromeDriver, nameFileLog); 
     _chromeService.EnableVerboseLogging = true;

     //creating chromeOptions, to set the profile preferences
     _chromeOptions = new ChromeOptions();

     //using Dictionary to pass parameter name (string) and json object to AddUserProfilePreference.
     Dictionary<string, object> prefs  = new Dictionary<string, object>();
     prefs.Add("downloadFile", "{\"recentDestinations\": [{\"id\": \"Save as PDF\", \"origin\": \"local\", \"account\": \"\" }],\"version\":2,\"isGcpPromoDismissed\":false,\"selectedDestinationId\":\"Save as PDF\"}");
     prefs.Add("pathFinalFile", "C:\\Users\\" + Environment.UserName + "\\Downloads\\");

     //using the dictionary values to set the parameters
     _chromeOptions.AddUserProfilePreference("printing.print_preview_sticky_settings.appState", prefs["downloadFile"])
     _chromeOptions.AddUserProfilePreference("savefile.default_directory", prefs["pathFinalFile"]); 

     //disable 'chrome is being controlled by automated test software' bar
     _chromeOptions.AddUserProfilePreference("useAutomationExtension", false);
     _chromeOptions.AddExcludedArgument("enable-automation");

     //using --kiosk-printing to enable "silent printing"
     _chromeOptions.AddArgument("--kiosk-printing");

     //creating webdriver
     _driver = new ChromeDriver(_chromeService, _chromeOptions);
     _driver.Navigate().GoToUrl("https://applitools.com/blog/selenium-4-chrome-devtools/");
     _driver.Manage().Window.Maximize();

     //run javascript to print
     _driver.ExecuteJavaScript("window.print();");

     //is done!
}

如果窗口“另存为”仍然打开，则说明某些参数不正确。